An apparatus of the type described hereinabove is known from U.S. Pat. No. 7,922,731 B2 for example. It is employed, in particular, in the course of a surgical procedure in order to fix a spinal column stabilization system as described above to a spinal column. The implantation of such spinal column stabilization systems originally began using open techniques. This means that an operating surgeon has a free view of the site of the operation. However, in order to minimise operational traumata for the patients, the operational techniques that were also known for the implantation of spinal column stabilization systems have been further developed with the goal of also implanting such spinal column stabilization systems in a minimally invasive manner.
In the case of the apparatus known from U.S. Pat. No. 7,922,731 B2, the bone screws of the spinal column stabilization system are each initially placed in a vertebra. The multi-function sleeve of this spinal column stabilization system is then seated on the forklike head which accommodates the rod-shaped connecting element. The known multi-functional sleeve incorporates guidance members in order to establish a firm grip on the forklike head of the screw. However, it is difficult to seat such a multi-function sleeve on the screw when there is only one minimally invasive access to the vertebra.
Therefore, it would be desirable to provide a surgical apparatus of the type described hereinabove which allows a simpler employment thereof in minimally invasive surgical procedures.